X-Ray Detector Based on All-Inorganic Lead-Free Cs2AgBiBr6 Perovskite Single Crystal

In this paper, single crystals (SCs) of the Cs
₂
AgBiBr
₆
double perovskite were grown using the method of crystallization from a supersaturated solution. It was shown that the natural crystal growth surface of the perovskite with perfect crystal quality is along the (111) plane by X-ray diffraction (XRD) and high-resolution transmission electron microscope (HRTEM) analyses. The fabricated high-sensitivity X-ray detector based on the Cs
₂
AgBiBr
₆
SCs with vertical structure achieved detection sensitivity up to
$316~\mu $
CGyair
⁻¹
cm
⁻²
under bias voltage of 18 V. Furthermore, the frequency noise characteristics of the device under different posttreatment processes were systematically analyzed, which indicated that the combination of thermal annealing and isopropanol rinsing can suppress field-driven ion migration and surface conduction channel, thereby increasing the resistivity of the perovskite material and reducing the noise current of the device. Our results revealed that the Cs
₂
AgBiBr
₆
SCs-based X-ray detector with high sensitivity and low cost has a great potential for application in manufacturing lead-free and stable radiation detection electronics in the future.